21001200220 has 96 divisors (see below), whose sum is σ = 59214629376. Its totient is φ = 6042297600.

The previous prime is 21001200217. The next prime is 21001200221. The reversal of 21001200220 is 2200210012.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 21001200197 and 21001200206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001200221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 504486 + ... + 544525.

It is an arithmetic number, because the mean of its divisors is an integer number (616819056).

Almost surely, 2^21001200220 is an apocalyptic number.

21001200220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21001200220 is an abundant number, since it is smaller than the sum of its proper divisors (38213429156).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21001200220 is a wasteful number, since it uses less digits than its factorization.

21001200220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1049051 (or 1049049 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 10.

Adding to 21001200220 its reverse (2200210012), we get a palindrome (23201410232).

The spelling of 21001200220 in words is "twenty-one billion, one million, two hundred thousand, two hundred twenty".